package xyz.maxwellj.mapm

import fuel.Fuel
import fuel.get
import java.io.File
import java.math.BigInteger
import java.security.MessageDigest
import kotlin.system.exitProcess
import org.tukaani.xz.XZInputStream
import java.io.*
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream
import java.io.BufferedInputStream
import java.io.FileInputStream
import java.nio.file.Files
import java.nio.file.Paths


fun uncompressXZFile(inputFile: String, outputFile: String) {
    XZInputStream(FileInputStream(inputFile)).use { input ->
        FileOutputStream(outputFile).use { output ->
            input.copyTo(output)
        }
    }
}

fun unarchiveTarFile(tarFilePath: String, outputDirectoryPath: String) {
    val tarFile = File(tarFilePath)
    val outputDir = File(outputDirectoryPath)

    if (!outputDir.exists()) {
        outputDir.mkdirs()
    }

    TarArchiveInputStream(BufferedInputStream(FileInputStream(tarFile))).use { tarIn ->
        var entry = tarIn.nextTarEntry
        while (entry != null) {
            val outputFile = File(outputDir, entry.name)
            if (entry.isDirectory) {
                outputFile.mkdirs()
            } else {
                outputFile.parentFile.mkdirs()
                Files.copy(tarIn, Paths.get(outputFile.absolutePath))
            }
            entry = tarIn.nextTarEntry
        }
    }
}

// hurrah for https://stackoverflow.com/questions/64171624/how-to-generate-an-md5-hash-in-kotlin!
fun md5(input:String): String {
    val md = MessageDigest.getInstance("MD5")
    return BigInteger(1, md.digest(input.toByteArray())).toString(16).padStart(32, '0')
}

suspend fun main() {
    println("Welcome to Mapm! What would you like to do? Type help for some help.")
    
    val userInput = readln()
    if (userInput == "grab") {
        println("What would you like to grab?")
        val userInput = readln()
        val linkToUse = "https://git.maxwellj.xyz/mapm/stable/raw/branch/main/$userInput"
        val dingus = Fuel.get(linkToUse).body.string()
        println(dingus)
        val file = File("/usr/mapm/tmp/$userInput.tar.xz")
        // file.writeBytes((Fuel.get(dingus).body.string()).toByteArray())
        val fileBytes = Fuel.get(dingus).body.bytes()
        file.writeBytes(fileBytes)
        val fileChecksum = Fuel.get("https://git.maxwellj.xyz/mapm/stable/raw/branch/main/$userInput.hash").body.string()
        if (fileChecksum == md5(file.readText())) {
            println("Checksum matches!")
            uncompressXZFile(inputFile = "/usr/mapm/tmp/${userInput}.tar.xz", outputFile = "/usr/mapm/tmp/${userInput}.tar")
            unarchiveTarFile(tarFilePath = "/usr/mapm/tmp/${userInput}.tar", outputDirectoryPath = "/usr/mapm/")
            Runtime.getRuntime().exec("chmod +x /usr/mapm/${userInput}")
            println("Finished!")
            exitProcess(0)
        } else {
            println("Checksum doesn't match! Aborting...")
            println("Please tell Max or your app's developer to use mapm to generate a new checksum. If the checksum is right, check your internet connection security.")
            exitProcess(1)
        }
    } else if (userInput == "delete") {
        println("What would you like to delete?")
        val userInput = readln()
    } else if (userInput == "checksum") {
            println("What file would you like to generate a checksum of? Type the whole path")
        val userInput = readln()
        val file = File(userInput)
        println("Checksum of that file is ${md5(file.readText())}")
    }
}